. >> reporter: and running mate paul ryan hanging success on the debates. >> the debate phase in this campaign. we will make this case in our debates. >> reporter: that debate will be held here in denver. in the meantime, mitt romney held a rally here behind me. most of his t-unken. preparing for the most important night of his polil cpdaac ner. >>> and president obama is spending his last full day of debate prep at a resort outside st to deliver pza at abc political analyst matt dowd says mr. obama's advisers are focused on helping the president trim his often lengthy answers. to o bes often lengthy answers. answer questions, short, concisely, and to the point, and so it's much more like his mannerisms and his style and the way he comes across as 'posed to information in this. >> so style, not substance, i guess? i don't know. >> sounds like it. >> both parties say the first debate traditionally helps the challenger just by appearing on stage as an alternative. abc news live coverage of the first presidential debate, begins tomorrow night at 9:00 p.m. eastern, diane sawyer, george st